I wanted to spend time on the presuppositions of Kant's philosophy in the last post because like much in Kant's philosophy they seem like they're open to easy attack. They're not. I wanted to draw a close connection between the presuppositions of Kant's moral philosophy and modernity generally, specifically modern technology and modern science. Kant and the rest of us assume a radical fact/value distinction because we have come to have a particular kind of understanding of what it means for something to belong to nature. The reason we have this particular understanding of nature—call it rational or naturalistic or non-superstitious—is not because some people were really smart and decided to think of it that way. We have this understanding of nature because of modern experimental methods which were invented and developed in the Islamic world in the Middle Ages and which were taken over by people in Europe. So it's really a kind of technique or practice which gives rise to science. Science then allows us to create even more powerful instruments, which then allows us to refine our science, and so on. Which came first in this chain of events, the technology or the science, I'll leave for another time. The point is that Kant's assumptions don't come out of thin air. They're in fact real world accomplishments.
If we accept these assumptions, then we can see why Kant believes the good, whatever it is, cannot be any object. If the good is an object, it can only relate to my will either contingently or necessarily. Assume it relates to it contingently. I am therefore under no obligation to desire it, so morality collapses. Assume it relates to it necessarily. Then it destroys my freedom. As long as the good is any object, I'm either not obligated to pursue it, or I'm forced to pursue it. Both outcomes make morality impossible.
To get out of this paradox, Kant attempts something very clever. He says the will does not will an object, it just wills itself. This seems like a strange idea, but it's really the only way out. Whatever the will wills, it cannot will its own lack of freedom. That's just a logical and performative contradiction. Even if I decide I don't want to be free anymore and I'm just going to do what the Pope says, it's still my choice to do that. There's just no way to escape from freedom. No matter what, the will must at least will itself.
This seems like a rather thin idea. At least when I'm willing an object or some state of affairs, I can think about that object and its properties. I can think about whether one of those properties is "goodness", and if it is, I can go after it. Kant is saying that is precisely what I cannot do. I have to will freedom itself. But pure freedom doesn't have any content. It doesn't look like anything or smell like anything. It's just a pure capacity.
But that's exactly why Kant's solution is so successful. If we're not thinking about anything in particular when we think about an absolutely free will, then we're not trapped in the paradox that arises when we start with a concept of a good object or a good end. But more importantly, since we are willing nothing but willing itself (or the capacity to act freely), then we are willing something that is absolutely universal. Since we're not tied down to any particular content here, what we will in willing freedom applies not just to us but to anyone, and it applies irrespective of whatever particular desire they have. The only maxims of action that accord with pure freedom are those which can be carried out by any rational agent irrespective of their particular desires. In other words, they are universal laws.
Here's how it works. Let's say that I borrow money which I promise to pay back, but when it comes time to pay back the money, I choose not to. Is my action right or is it wrong? A non-Kantian would answer this by appealing to human happiness, virtue, the 10 Commandments, or whether it maximizes utility. Kant tries something different. He says, imagine you do not pay back the money. Furthermore, imagine that every single person who ever enters into your same position also does not pay back the money, and that this happens as surely as releasing a stone causes it to fall to the ground. In addition, imagine that every person on earth already knows that every single person who ever enters into your same position does not pay back the money. Assuming this is the case, is the action you propose even possible?
Well, if we assume all these things, then no, the action does not seem possible. If no one ever paid back money when they said they would, no one would ever lend money in the first place. The institution of lending simply wouldn't exist, and so you would never have the chance to go back on your promise to repay. If you choose not to pay back the money, you are also covertly choosing to live in a world wherein your action is impossible. Your action is not just your own. It also implicitly legislates for everyone else at the same time. And by doing that, you're in this case willing a contradiction, since it could never be the case that everyone could perform that action.
So what? Why is a contradiction immoral?
Because it amounts to making an exception for yourself. You're excluding yourself from the community of human beings. You're saying there's something particular about you that makes the action okay for you but not for anyone else. It's elitist, of course, but the real problem is that it's particularistic and so it invokes all the problems that come with willing any "good" object. Whatever free action is, it has to have logical consistency. If it doesn't, it's not free. But being a free-rider in the moral community turns out to be the most basic form of logical inconsistency in action.
I wouldn't call it a beautiful idea, but it accords with a lot of our intuitions about morality. There's no such thing as particular morality. We might argue about whether or not it's ever okay to kill another human being, but we're going to argue a lot less about whether you being a woman or black or short or incredibly smart or whether you like the color red has any bearing on the question. The idea that our acts are legislative captures nicely basic facts of human sociality, but it also gets at the idea that morality has a generalizable structure. I'm not just wondering whether this action is good for me. (That might be an important question, but it's not a morally relevant one.) The question is whether it's good for anyone. The idea that action x is morally good but is not binding on you is a contradiction. Kant's move to think about the conditions of willing itself gets at that idea.
Of course there are criticisms one can make of this idea, and they've been made many times. That's fine, but I think we need to keep some things in mind as we do that. The formalistic approach Kant uses here sounds stuffy and professorial, but we do get neat things like human dignity out of it. (One implication of the moral law is that you are to treat people always as ends and never merely as means.) We also get a compelling albeit somewhat abstract argument against elitism and exceptionalism. If you're going to move away from these ideas, you had better do so because it's necessary, not because you don't like how the word "duty" sounds or some other theory appears sexier.
These ideas are still pretty foundational for modern life, despite how it appears when you're studying them in school or something. There's arguably something very Kantian every time a person or group of people stand up and demand dignity and fair and equal treatment or when people protest corruption. Sure, you can complain about the details of the arguments. But the idea that these thoughts are somehow passé and that we could do so much better listening to Nietzsche or Heidegger would be dangerous if it didn't sound so absurd.